1. Field of the Invention
The present invention relates to a structure of the direction control device of a joystick, and especially to a double axes input means with two infrared detector sets which are preferably used in the direction control of a joystick.
2. Background of the Invention
In the prior-art joystick, the movement of the joystick is controlled linearly, that is, the data of X axis and Y axis are obtained by modulating through a varied resistor. It is desired to obtain the input data of X axis and Y axis to plot a vector of absolute linear coordinates (as shown in FIG. 1). In that, the original point (0, 0) is installed on the center, for example (50, 50), of a vector of absolute linear coordinates so that it may be correspondent to any point of display screen.
But the resistance of a varied resistor is adjusted by the rotation of a resistor adjusting rod, thus the linear absolute coordinate vector formed by the resistance thereof can not attain the object of a linear vector. Instead, it is presented as a vector of absolute nonlinear coordinates, as the points b and c shown in FIG. 1--1. Thus, a manual fine adjustment is necessary to reset the device (as shown in FIG. 1-2). Although the original point may thereby be reset, the obtained absolute coordinate vector figure is still nonlinear, i.e. the ideal condition shown in FIG. 1 can not been presented. Furthermore, after a long period of rotation of the varied resistance, the carbon film is easy to break through extended periods of contact and friction, the correct resistance will be lost. Accordingly, the of correctness of nonlinear vector figure is further effected.
Since the prior-art joystick varies the linear signal due to the friction of the varied resistance, and each time, a fine adjustment is needed to reset the device, it is necessary to provide an improved structure of the direction control device of a joystick. By a {character pullout} shape opening, a central reset hole and two infrared detector sets, when the infrared detectors have detected the movement of the fans, the signals 0 and 1 will be generated and used as data for controlling the X axis and Y axis about the direction of the joystick. When the joystick has been released, the fan shaped encoder structures of the input axes will be recycled back to the central point so that another infrared detector will pass through a reset hole. Thus, the present invention may be controlled sensitively and has a precise reset effect.